Graduate Theses & Dissertations

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Incidental Take and Population Dynamics of Nesting Birds in a Red Pine (Pinus resinosa) Plantation Under Single-Tree Selection Harvesting
I determined the direct influence of single-tree selection harvesting on the daily nest survival rates and nest success of 5 focal bird species within a monotypic red pine (Pinus resinosa) plantation on the western edge of the Oak Ridges Moraine in southern Ontario, Canada. I located and monitored 290 nests during the 2012 and 2013 breeding season. I used the logistic-exposure method to evaluate the daily nest survival rates of American Robin (Turdus migratorius), Eastern Wood-pewee (Contopus virens), Ovenbird (Seiurus aurocapilla), Rose-breasted Grosbeak (Pheucticus ludovicianus), and Red-eyed Vireo (Vireo olivaceus). Only five nests were destroyed as a result of forestry activity over the study period. Neither daily nest survival rates nor nest success of these focal species were substantially affected by single-tree selection harvesting. I also monitored the impact of single-tree selection harvesting on the density and territory size of 4 of 5 focal species. Ovenbird had a significantly smaller territory size but decreased density in the harvested areas. Although not significant, Eastern Wood-pewee and Red-eyed Vireo tended to have higher densities and larger territory sizes in harvested areas, whereas Rose-breasted Grosbeak showed a mixed effect as density was higher while territory size was smaller. Single-tree selection produces minor to moderate disturbance that takes place locally over a short period of time. As a result, nests that are indirectly disturbed by nearby harvesting, felling trees and mechanical operations and are not destroyed remain and adults do not appear to abandon eggs or young from the disturbance. Habitat alteration from harvesting of the general forest structure and especially the forest floor must be minimized in order to conserve forest bird species diversity. Further research examining incidental take using various intensities of single-tree selection harvesting would provide important insight into maintaining avian and forest diversity by means of forest management. Author Keywords: daily nest survival rates, forest management, Incidental Take, nest success, red pine monotypic forest, single-tree selection harvesting
Factors Influencing the Prioritization of Sites for Conservation on Private Land in Southern Ontario
Conservation organizations use strategic prioritization methods to order complex environments, evaluate landscapes, and distribute efficiently resources for conservation. This study explores how strategic prioritization decisions are made, drawing on a case study of the Nature Conservancy of Canada (NCC). This thesis identifies the factors affecting prioritization and their influence on the public perception of the NCC. The case study revealed that the NCC utilizes comprehensive science-based methods when prioritizing for conservation but its methods are also influenced by the 'opportunity function' (funding, threats, public/political support). How these factors are communicated depends on the audience (e.g. NCC Conservation Blueprints stress the scientific value of the environment; the NCC uses its media sources to emphasize the human-environment connection). These differences indicate the multi-dimensional nature of planning for conservation, its links to values emerging from science, politics, and society, and the need for collaborative conservation efforts and earning and maintaining public trust. Author Keywords: biodiversity conservation priorities, collaboration, Nature Conservancy of Canada, opportunity function, private conservation organizations, science-based conservation
Beyond Habitat
My objective was to understand how individual variation, in conjunction with variation in habitat, can affect individual and population-level variation in animal space use. I used coyotes (Canis latrans) as a model species to investigate the roles of hybridization, an inherited intrinsic factor, and spatial memory, a learned intrinsic factor, on space use. I used a diversity of methods and approaches, including meta-regression, multiple imputation, simulations, resource selection functions, step selection functions, net-squared displacement analysis, and survival analysis. A major contribution was my investigation of the performance of multiple imputation in a meta-regression framework in Chapter 2. My simulations indicated that multiple imputation performs well in estimating missing data within a meta-regression framework in most situations. In Chapter 3, I used published studies of coyote home range size in a meta-regression analysis with multiple imputation to examine the relative roles of hybridization and environmental variables on coyote home range size across North America. I found that hybridization with Canis species was a leading factor driving variation in coyote space use at a continental scale. In Chapter 4, I used telemetry data for 62 coyotes in Newfoundland, Canada, to investigate the influence of cognitive maps on resource use. I found that resident coyotes used spatial memory of the landscape to select or avoid resources at spatial scales beyond their immediate sensory perception relative to transient coyotes, presumably increasing their fitness. Taken together, my dissertation demonstrates that intrinsic factors, such as genetic ancestry and spatial memory, can have substantial influences on how animals use space at both individual and population levels, and at both a local and a continental scales. Author Keywords: canis latrans, hybridization, meta-regression, multiple imputation, Newfoundland, spatial memory
Lithic Raw Material Characterization and Technological Organization of a Late Archaic Assemblage from Jacob Island, Kawartha Lakes, Ontario
The objective of this thesis is to document and characterize the raw material and technological organization of a Late Archaic assemblage from Jacob Island, 1B/1C area (collectively referred to as BcGo-17), Peterborough County, Kawartha Lakes, Ontario. The purpose of this research is to gain a greater understanding of the Late Archaic period in central Ontario; particularly information on locally available raw material types (i.e., Trent Valley cherts) and regional interaction. My aim is to define the range of materials exploited for stone tool production and use, and to explore how variation in material relates to variation in economic strategies; I also complete a basic technological study. The collected data is then compared to temporally and geographically similar sites, and used to interpret possible relationships between acquisition practices, technology choices, and mobility. It was found that although the assemblage agrees with some of the mobility and raw material utilization models from south-western Ontario, many do not explain what was occurring on Jacob Island. Author Keywords: Archaic, Lithic Economic Strategies, Lithic Raw Material, Lithic Technology, Ontario Archaeology, Trent Valley
Reassessing Bioarchaeological Sex Determination and Research into Gender at the Early Anglo-Saxon Worthy Park Burial Ground Round in Hampshire, England
When bioarchaeologists investigate ancient gender identity, they typically place skeletal remains into one of six sex assessment categories: male, female, possible/probable male, possible/probable female, ambiguous, and indeterminate. However, the study samples are often reduced to male and female reproducing a male/female gender and sex binary prevalent in the "Western" cultural milieu and bioarchaeology when inferences are made about gender and sex in the past. In order to allow for the existence of non-binary cultural genders and biological sexes, this thesis: 1) demonstrates the multitude of ethnographic, ethnohistoric, historic, and medical evidence relating to non-binary sex and gender expression; 2) tests a method inspired by Whelan (1991) that looks at gender as an identity not fully inspired by biological sex; 3) keeps all sex assessment categories used by bioarchaeologists separate in analysis and interpretation; and 4) analyses patterns relating to all available material culture and biological attributes in a mortuary sample to investigate gender identity. This thesis used the Early Anglo-Saxon (470-600 AD) burial ground at Worthy Park in Hampshire to achieve these objectives. This thesis found that when examining all sex assessment categories among all mortuary variables, only the male sex was clearly defined by its mortuary assemblage. This suggests a one gender structure corresponding to linguistic evidence for one gender in Old English. Author Keywords: Anglo-Saxon, Bioarchaeology, Gender identity, Mortuary archaeology, Osteoarchaeology, Sex determination
Environmental Health Management Practices in Indigenous Communities
Environmental factors play a critical role in the health and well-being of people worldwide and the distribution of the burden of disease associated with environmental causes is disproportionately high in marginalized populations, including First Nations. In this way, environmental health problems are as much social and political problems as environmental and must be addressed as such. In Canada, the division of responsibilities for environmental health, in combination with the jurisdictional complexities of health and environment regulation and service provision on-reserve creates a First Nations environmental health management system with significant gaps. This research set out to explore the question: What are the current strengths and challenges in First Nations environmental health policy and management? A qualitative exploratory design organized in two stages and employing key informant interviews, document review and a community case study was used to examine this topic. In the first stage a review of existing programs and policies applicable to Ontario First Nations and a series of interviews with key experts on the topic in the province were conducted. A conceptual framework of the core elements affecting environmental health management in First Nations communities was developed and then applied to a case study with Mississauga First Nation in Northern Ontario. The framework included five core elements: Environmental Health Jurisdiction and Responsibility; Participation in Environmental Health Decision-Making; Access to Environmental Health Resources, Communication of Environmental Health Information; and, Role and Influence of Leadership. The findings indicate that "internal" issues, like community-based decision-making and support for environmental health initiatives seem to be least affected by the "external" issues such as access to federal funding. The "internal" issues were also shown to be critically important factors having impacts on environmental health management practices and policies in Mississauga First Nation. While there are countless barriers associated with the "external" factors that have significant impacts on environmental health management practices and policies, this research suggest that the "internal" factors can potentially be the most important factors in creating positive change in this area and as a result warrant further study in order to improve the state of environmental health issues in First Nations. Author Keywords: Community, Environmental Health, First Nations, Framework, Policy
From Negation to Affirmation
Forensic scientific practice is conventionally understood as a solution to absence. With every technological advance the power and span of the archive grows and with it revives hopes of uncovering facts and locate bodies that might put genocide denial and/or negationism to rest. Destruction, however, continues to define the reality and conditions for testimony in the aftermath of mass atrocity. This means that even as forensic scientific practice grows in its capacity to presence that which was previously unpresentable, destruction and the concomitant destruction of archive require that we consider what it means to remember with and without the archive alike. This dissertation explores the impact of forensic science on cultural memory through a choice of two case studies (set in Kosovo and Srebrenica respectively) where forensic scientific methods were involved in the investigation of atrocities that were openly denied. This dissertation makes an agnostic argument that the biblical example of the empty tomb can serve as a paradigm to understand the terms of witnessing and testifying to absence in the era of forensic scientific investigations. Specifically, it posits the following theses with regards to the empty tomb: it is a structure and an event that emerges at the intersection of forensic science’s dual property as an indexical technique and as a witness function, it cannot be validated through historiographic or forensic scientific methods (it is un-decidable) and as such serves as a corrective the fantasy of the total archive, is represented in the contemporary genre of forensic landscape; and because it breaks with the forensic imperative, it compels alternative uses for testimony and memorial practices that need not be defined by melancholia as it can accommodate forms of testimony that are joyous and life affirming. Author Keywords: Absence, Archive, Forensic, Memory, Testimony, Witness
Detecting anti-estrogens and anti-androgens in surface waters impacted by municipal wastewater discharges and agricultural runoff
This study focused on detecting 22 target anti-estrogenic and anti-androgenic compounds in surface waters influenced by both discharges of municipal wastewater and agricultural runoff in Canada and Argentina. Polar organic chemical integrative samplers (POCIS) were used to monitor the target compounds in surface waters. The removals of the target compounds in a municipal wastewater treatment plant (WWTP) in Canada were also evaluated. In both Canada and Argentina pesticides with potential anti-estrogenic and anti-androgenic activities were detected in the surface waters. The highest concentrations were found in Argentina (up to 1010 ng L-1) in areas impacted by heavy agricultural practices. Cyproterone acetate and bicalutamide were the only two anti-cancer drugs detected only at the Canadian study site, the Speed River, ON. In the Guelph WWTP, that discharges into the Speed River, these target compounds were not all efficiently removed (>70%) during treatment. Overall, this study provides insight to possible anti-estrogenic and anti-androgenic compounds that may be contributing to endocrine disrupting activities in surface waters. Author Keywords: Anti-androgens, Anti-estrogens, Cancer Therapy Drugs, Current use pesticides, Pharmaceuticals and Personal Care Products, Polar Organic Chemical Integrative Samplers
Comparative phylogeography in conservation biology
Phylogeographic histories of taxa around the Great Lakes region in North America are relevant to a range of ongoing issues including conservation management and biological invasions. In this thesis I investigated the comparative phylogeographic histories of plant species with disjunct distributions and plant species with continuous distributions around the Great Lakes region; this is a very dynamic geographic area with relatively recent colonisation histories that have been influenced by a range of factors including postglacial landscape modifications, and more recently, human-mediated dispersion. I first characterized four species that have disjunct populations in the Great Lakes region: (Bartonia paniculata subsp. paniculata, Empetrum nigrum, Sporobolus heterolepis, and Carex richardsonii). Through comparisons of core and disjunct populations, I found that a range of historical processes have resulted in two broad scenarios: in the first scenario, genetically distinct disjunct and core populations diverged prior to the last glacial cycle, and in the second scenario more recent vicariant events have resulted in genetically similar core and disjunct populations. The former scenario has important implications for conservation management. I then characterized the Typha species complex (T. latifolia, T. angustifolia, T. x glauca), which collectively represent species with continuous distributions. Recent microevolutionary processes, including hybridization, introgression, and intercontinental dispersal, obscure the phylogeographic patterns and complicate the evolutionary history of Typha spp. around the Great Lakes region, and have resulted in the growing dominance of non-native lineages. A broader geographical comparison of Typha spp. lineages from around the world identified repeated cryptic dispersal and long-distant movement as important phylogeographic influences. This research has demonstrated that comparisons of regional and global evolutionary histories can provide insight into historical and contemporary processes useful for management decisions in conservation biology and invasive species. Author Keywords: chloroplast DNA, conservation genetics, disjunct populations, invasive species, phylogeography, postglacial recolonisation
Utilizing Class-Specific Thresholds Discovered by Outlier Detection
We investigated if the performance of selected supervised machine-learning techniques could be improved by combining univariate outlier-detection techniques and machine-learning methods. We developed a framework to discover class-specific thresholds in class probability estimates using univariate outlier detection and proposed two novel techniques to utilize these class-specific thresholds. These proposed techniques were applied to various data sets and the results were evaluated. Our experimental results suggest that some of our techniques may improve recall in the base learner. Additional results suggest that one technique may produce higher accuracy and precision than AdaBoost.M1, while another may produce higher recall. Finally, our results suggest that we can achieve higher accuracy, precision, or recall when AdaBoost.M1 fails to produce higher metric values than the base learner. Author Keywords: AdaBoost, Boosting, Classification, Class-Specific Thresholds, Machine Learning, Outliers
Groundwater Recharge in a Managed Forest on the Oak Ridges Moraine, Southern Ontario
Groundwater recharge was estimated and compared in two open grasslands, three mixed deciduous forest stands (100+ years in age), three young red pine plantations (27 ¨C 29 years in age) and two old red pine plantations (62 ¨C 63 years in age) on the Oak Ridges Moraine, southern Ontario, Canada. Recharge was estimated using a 1-d water balance with measured precipitation, throughfall, stemflow, snowpack water equivalent and soil water storage, and modelled evapotranspiration. Throughfall distribution beneath red pine canopies showed no consistent variation with distance from the tree boles. Old red pines were not major stemflow producers and although the young red pines showed a slight tendency to focus stemflow (focussing ratio > 1), the inclusion of focussed stemflow when calculating recharge at the stand scale made little difference. Conversely, sugar maple (the predominant species in the mixed deciduous stands) showed a strong tendency to focus throughfall proximal to tree boles and produce large quantities of stemflow, resulting in relatively high soil moisture contents and enhanced opportunities for recharge within ~ 0.5 m of tree boles. Inclusion of these focussed inputs resulted in a ~ 11 ¨C 18 % increase in stand scale recharge estimates. The interpretation of land cover control on recharge was complicated by variations in soil texture between sites. Soil texture and its influence on soil water storage capacity resulted in temporal variations in recharge, with sites exhibiting large storage capacities producing less recharge in the fall and greater recharge in the spring than sites with limited storage capacities. Recharge estimates for the entire study period or seasonal values for sites grouped on the basis of soil water storage capacities showed a general trend of increasing recharge in the order: old red pine ¡Ö young red pine ¡ú mixed deciduous forest ¡Ö open grasslands. The disparity between the red pine plantations and the other sites was driven in large part by greater modelled evapotranspiration in the red pine plantations. The similarity in recharge between mixed deciduous forests and open grasslands was the result of focused inputs and less soil evaporation and transpiration in the mixed deciduous forests compared to the open grasslands. The results of this study suggest planting red pine on grasslands on the Oak Ridges Moraine will initially decrease recharge and this decrease will continue as the red pines mature. However, as the red pine plantations are succeeded by mixed hardwood stands recharge will recover to that of the initial grasslands. Author Keywords: Groundwater Recharge, Land Cover Type, Oak Ridges Moraine, Stemflow, Throughfall, Water Balance
origin and ecological function of an ion inducing anti-predator behaviour in Lithobates tadpoles
Chemical cues are used commonly by prey to identify predation risk in aquatic environments. Previous work has indicated that negatively-charged ions of m/z 501 are possibly a kairomone that induces anti-predator responses in tadpoles. This thesis found that this ion species: (i) is produced by injured tadpoles; (ii) exhibits increased spectral intensity with higher tadpole biomass; and (iii) is not produced by starved predators. These results refute the hypothesis that the ion is a kairomone, and rather support its role as an alarm cue released from tadpoles. High resolution mass spectrometry (HR-MS) revealed a unique elemental composition for [M-H]-, m/z 501.2886, of C26H45O7S-. Collision induced dissociation (CID) of ion m/z 501 formed product ions of m/z 97 and m/z 80, HSO4- and SO3-, respectively, indicating the presence of sulfate. Green frog (Lithobates clamitans) tadpoles exposed to m/z 501, and an industrial analogue, sodium dodecyl sulphate (NaC12H25O4S), exhibited similar anti-predator responses, thereby suggesting the potential role of organic sulfate as a tadpole behavioural alterant. Author Keywords: Alarm cue, Amphibian, Chemical Ecology, Mass spectrometry, Predator-prey interactions

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Format: 2024/03/28